On-chip detection of myoglobin based on fluorescence.
A disposable immunosensor cartridge was developed that allows antibodies to be immobilized on the surface for the detection of myoglobin, a marker for the early assessment of acute myocardial infarction (AMI) using fluorescence techniques. The anti-myoglobin antibody was immobilized on a polystyrene substrate based on covalent bonding via silanization. The immunosensor chip layers were fabricated from sheets by CO(2)-laser ablation. The functionalized polystyrene surfaces were characterized by contact angle measurement, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). After the antigen-antibody reaction as a sandwich enzyme-linked immunosorbent assay (ELISA) with a horseradish peroxidase-conjugated secondary antibody (HRP-anti-myoglobin), addition of fluorogenic substrate produced a fluorescent dye which was quantified on-chip using fluorescent technique. The immunosensor response was linear for myoglobin concentrations between 20 and 230 ng/ml (r=0.991, n=3). The detection limit was found to be 16 ng/ml, which is lower than the clinical cut-off value for myoglobin in healthy patients. This protocol could be extended to the detection of other important cardiac markers simultaneously in microchannels.
Darain
Farzana
F
Singapore-University of Washington Alliance, Biomedical Engineering Research Centre, Nanyang Technological University, Singapore. farzana@ntu.edu.sg
Yager
Paul
P
Gan
Kai Ling
KL
Tjin
Swee Chuan
SC
D015374:Biosensing Techniques / Q000295:instrumentation*; D004209:Disposable Equipment; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D008163:Luminescent Measurements / Q000295:instrumentation*; D046228:Microarray Analysis / Q000295:instrumentation*; D009211:Myoglobin / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*
D009211:Myoglobin